A spectrometer can typically disperse light of complex composition into a light spectrum, and may include a prism or a diffractive grating. Spectrometers can measure how much light is reflected from or transmitted through an object. Optical signals captured by a spectrometer can be developed on photographic films or be displayed and analyzed by a computer to give information on elemental compositions of the object to be measured. Based on optical principles, spectrometers are often used to observe, analyze, and process the structure and composition of matters. There are several advantages associated with spectrometers, including: high precision and accuracy, large measurement range, high speed and smaller amount of sample used, etc. Therefore, spectrometers have been widely used by agencies and institutes in the areas of metallurgy, geology, petroleum and chemical industries, medicine and health, and environmental protection. In addition, spectrometers are also a necessity for applications in military reconnaissance, space exploration, and resources and hydrological surveys.